The University of North Carolina-Chapel HIll (UNC) Clinical Center leads the eight Drug-Induced Liver Injury Network (DILIN) centers in terms of total subject recruitment and number of ancillary studies proposed and conducted. Dr. Paul Watkins has served as chair of the Steering Committee since 2003, when the network was created. Dr. Herbert Bonkovsky was PI at University of Connecticut, one of the original DILIN clinical sites, and since joining the UNC Clinical Center, he has continued to be very active in subject recruitment, ancillary study execution, and general guidance for the network. Dr. Paul Hayashi serves as co-chair of the network's Causality Assessment Committee. In addition to continuing in these administrative roles, we proposed to enroll at least 75 percent of DILIN subjects within 15 days of the initial health care encounter and to continue to lead the network in total subject recruitment (Specific Aim 1). We will work with DILIN investigators to further develop the LiverTox website and to create within it a new DILI diagnostic instrument that is accurate, simple, and practical for clinicians (Specific Aim 2). Finally, we propose conducting DILIN ancillary studies by utilizing fully the research infrastructure and international collaborations we have built specifically for this purpose (Specific Aim 3). With this funding, we believe the UNC Clinical Center would be well positioned to capitalize on the unprecedented resources we would help to develop within DILIN to achieve a level of mechanistic understanding that could revolutionize the diagnosis and management of DILI.